Method and apparatus for panning and tilting a camera

• US 20040196378A1
• Filed: 02/13/2004
• Published: 10/07/2004
• Est. Priority Date: 02/17/2003
• Status: Active Grant

• Current Assignee: Axis AB (Canon Inc.)
• Original Assignee: Axis AB (Canon Inc.)
• Inventors: Lundberg, Stefan, Kannermark, Per
• Granted Patent: US 7,525,576 B2
• Time in Patent Office: Days
• US Class Current: 348/207.99
• CPC Class Codes: H04N 23/45 for generating image signals from two or more image sensors being of different type or operating in different modes, e.g. with a CMOS sensor for moving images in combination with a charge-coupled device [CCD] for still images
• CPC Class Codes: H04N 23/58 Means for changing the camera field of view without moving the camera body, e.g. nutating or panning of optics or image sensors
• CPC Class Codes: H04N 23/665 involving internal camera communication with the image sensor, e.g. synchronising or multiplexing SSIS control signals
• CPC Class Codes: H04N 23/695 Control of camera direction for changing a field of view, e.g. pan, tilt or based on tracking of objects
• CPC Class Codes: H04N 25/41 Extracting pixel data from a plurality of image sensors simultaneously picking up an image, e.g. for increasing the field of view by combining the outputs of a plurality of sensors
• CPC Class Codes: H04N 5/2628 Alteration of picture size, shape, position or orientation, e.g. zooming, rotation, rolling, perspective, translation

Abstract

A camera is disclosed which includes: at least two image sensors, an image sensor selector, a multiplexer and an image processor. The at least two image sensors are configured to synchronously output successive pixels of image data. The image sensor selector is responsive to a pan and/or tilt signal input associated with a target view of the image data provided by the at least two image sensors, to output a select signal indicating for each synchronous output of pixels from the at least two image sensors a selected one of the at least two image sensors delivering a pixel within the target view. The multiplexer has inputs, an output, and a control input. The multiplexer inputs are each coupled to a corresponding one of the at least two image sensors to receive the successive pixels of image data there from. The multiplexer is responsive to the select signal from the image sensor selector at the control input to output the selected one of the pixels at the input which is within the target view during each pixel clock cycle. The image processor has an input coupled to the output of the multiplexer for processing the pixels within the target view.

Claims

1. A camera comprising:

at least two image sensors configured to synchronously output successive pixels of image data;

an image sensor selector responsive to a pan and/or tilt signal input associated with a target view of the image data provided by the at least two image sensors, to output a select signal indicating for each synchronous output of pixels from the at least two image sensors a selected one of the at least two image sensors delivering a pixel within the target view;

a multiplexer with inputs, an output, and a control input, and the multiplexer inputs each coupled to a corresponding one of the at least two image sensors to receive the successive pixels of image data there from, and the multiplexer responsive to the select signal from the image sensor selector at the control input to output the selected one of the pixels at the input which is within the target view during each pixel clock cycle; and

an image processor with an input coupled to the output of the multiplexer for processing the pixels within the target view.

2. The camera of claim 1, wherein the image processor further rearranges each of the multiplexed pixels from the multiplexer to conform with an associated location of each respective pixel in the target view.

3. The camera of claim 1, wherein the image sensor selector includes responsiveness to multiple pan and/or tilt signal inputs from multiple users to output the select signal to the multiplexer which effects a time-division multiplexing of the pan/tilt instructions of multiple users.

4. The camera of claim 1, wherein the image data output by each of the at least two image sensors correspond with at least one of contiguous portions of a monitored area, separate portions of the monitored area and partially overlapping portions of the monitored area.

5. The camera of claim 1, wherein the image data output by each of the at least two image sensors corresponds with substantially discrete fixed portions of a monitored area.

6. The camera of claim 1, wherein the image processor further compresses the target view including each sequential image thereof.

7. The camera of claim 1, wherein the image processor further stitches associated overlapping portions of the target view derived from a first and a second of the at least two image sensors to one another.

11. The camera of claim 1, wherein the image sensor selector includes responsiveness to multiple pan and/or tilt signal inputs from multiple users to output the select signal to the multiplexer which effects a time-division multiplexing of the pan/tilt instructions of multiple users.

8. A camera to capture sequential images from a monitored area, and the camera comprising:

at least two image sensors each configured to deliver a rasterized pixel stream obtained from a corresponding portion of the monitored area;

an image sensor selector responsive to an input signal corresponding with at least one of a pan instruction and a tilt instruction to effect a corresponding logical movement of a target view within the monitored area, and to output a select signal corresponding with a location of the target view;

a multiplexer coupled to the at least two image sensors and the image sensor selector, and the multiplexer responsive to the select signal from the image sensor selector to multiplex from each of the rasterized pixel streams of the at least two image sensors those pixels required to form sequential images of the target view, thereby avoiding the multiplexing of pixels not required for the target view; and

an image processor to process the multiplexed pixels from the multiplexer into the target view.

9. The camera of claim 8, further comprising;

a timing generator synchonizing the delivery of the rasterized pixel streams from the at least two image sensors to the multiplexer; and

the multiplexer accepting as an input a first and second rasterized pixel streams from a first and second of the least two image sensors respectively and the multiplexer mutiplexing as an output one pixel from a selected one of the first and second rasterized pixel streams in an associated timing interval, thereby avoiding the multiplexing of a pixel from a remaining one of the first and second rasterized pixel streams, not required for the target view.

10. The camera of claim 8, wherein the image processor further rearranges each of the multiplexed pixels from the multiplexer to conform with an associated location of the respective pixel in the target view.

12. The camera of claim 8, wherein the rasterized pixel streams obtained by the at least two image sensors correspond with at least one of contiguous portions of the monitored area, separate portions of the monitored area and partially overlapping portions of the monitored area.

13. The camera of claim 8, wherein the rasterized pixel streams obtained by the at least two image sensors correspond with substantially discrete fixed portions of the monitored area.

14. The camera of claim 8, wherein the image processor further compresses the target view including each sequential image thereof.

15. The camera of claim 8, wherein the image processor further stitches associated overlapping portions of the target view derived from a first and a second of the at least two image sensors to one another.

16. A method for capturing sequential images from a monitored area, and the method comprising:

deliver at least two rasterized pixel stream each obtained from a corresponding portion of the monitored area;

generating a select signal corresponding with a location of the target view within the monitored area responsive to an input signal corresponding with at least one of a pan instruction and a tilt instruction;

multiplexing in response to the select signal generated in the generating act, from each of the rasterized pixel streams delivered in the delivering act, those pixels required to form sequential images of the target view, thereby avoiding the multiplexing of pixels not required for the target view; and

processing the multiplexed pixels from the multiplexing act into sequential images comprising the target view.

17. The method of claim 16, further comprising;

synchonizing the delivery of the at least two rasterized pixel streams; and

mutiplexing as an output one pixel from a selected one of the first and second rasterized pixel streams in an associated timing interval, thereby avoiding the multiplexing of a pixel from a remaining one of the first and second rasterized pixel streams, not required for the target view.

18. The method of claim 16, further comprising:

rearranging each of the pixels multiplexed in the multiplexing act to conform with an associated location of the respective pixel in the target view.

19. The method of claim 16, wherein the generating act further comprises:

generating the select signal to effect in the multiplexing act a time-division multiplexing of the pan/tilt instructions of multiple users.

20. The method of claim 16, wherein the rasterized pixel streams delivered in the delivering act correspond with at least one of:

contiguous portions of the monitored area, separate portions of the monitored area and partially overlapping portions of the monitored area.

21. The method of claim 16, wherein the rasterized pixel streams delivered in the delivering act correspond with substantially discrete fixed portions of the monitored area.

22. The method of claim 16, wherein the processing act further comprises:

compressing the target view including each sequential image thereof

23. The method of claim 16, wherein the processing act further comprises:

stitching associated overlapping portions of the target view delivered from the at least two rasterized pixel streams.